The present invention relates to a rotary regenerative heat exchanger that comprises a series of sector-shaped compartments of heat absorbent material connected to and supported in radial juxtaposition outward from a central rotor post to comprise the rotor for the heat exchanger. The rotor includes a central trunnion that is rotatably supported by bearing means carried by independent housing structure. The rotor is subjected to hot and cold fluids whereby when rotated about its axis, heat from the hot fluid is transferred to the cool fluid through the intermediary of the heat absorbent rotor.